This is a request for support of a workshop in Genito-Urinary (GU) Cancer Immunology involving both clinicians and basic scientists active in this type of research. This is an opportune time for the workshop. With approximately 50 single investigators or research groups in this relatively new field, there is now sufficient information available to give the meeting substance. At the same time, further progress is hindered because all investigators face a number of common, unsolved problems. The proposed workshop is rather uniquely addressed to the present concerns of all of these investigators. All of the major human urological cancers will be considered, along with the relevant animal models, with exclusive emphasis on immunology, immunotherapy, and related topics. The workshop chairman has attempted to contact every active research group, and the preregistration response has been excellent. The workshop participants will meet together for a three-day period in a "retreat" type of setting. The meeting format and physical arrangements are all designed to encourage free discussion, sparked by brief data presentations and critiques of experimental method by the participants. An internationally recognized faculty of discussion leaders will guide the group through a critical evaluation of present knowledge and a careful consideration of current problems. The entire proceedings will be photographed and recorded on tape for thorough editing and subsequent publication.